mherrb/echoc
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Remove the use of Posix real-time functions.

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The only reason to use clock_gettime() was to take a timestamp
in the signal handler. This is not needed anymoire, so improve
portability by sticking to gettimeofday() and setitimer().
This commit is contained in:
Matthieu Herrb 2012-07-31 08:26:05 +02:00
parent 1882a84527
commit c00525adaa
2 changed files with 20 additions and 64 deletions
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2
Makefile
View file

@ -5,7 +5,7 @@ SRCS= echoc.c
OBJS= $(SRCS:%.c=%.o) OBJS= $(SRCS:%.c=%.o)
LIBS= -lrt LIBS=
all: $(PROG) all: $(PROG)

82
echoc.c
View file

@ -36,7 +36,7 @@ struct sockaddr *server;
socklen_t serverlen; socklen_t serverlen;
unsigned int seq = 0; unsigned int seq = 0;
int disconnected; int disconnected;
struct timespec sent; struct timeval sent;
#define THRESHOLD 10 #define THRESHOLD 10
@ -47,7 +47,7 @@ usage(void)
} }
static void static void
send_packet(bool timestamp) send_packet(int unused)
{ {
if (sendto(sock, &seq, sizeof(seq), 0, server, if (sendto(sock, &seq, sizeof(seq), 0, server,
serverlen) != sizeof(seq)) { serverlen) != sizeof(seq)) {
@ -59,36 +59,6 @@ send_packet(bool timestamp)
seq++; seq++;
} }
static void
timer_handler(int unused)
{
send_packet(!disconnected);
}
static void
timespec_substract(struct timespec *result,
const struct timespec *x, const struct timespec *y)
{
struct timespec yy;
memcpy(&yy, y, sizeof(struct timespec));
/* Carry */
if (x->tv_nsec < y->tv_nsec) {
long sec = (y->tv_nsec - x->tv_nsec) / 1000000000 + 1;
yy.tv_nsec -= 1000000000 * sec;
yy.tv_sec += sec;
}
if (x->tv_nsec - y->tv_nsec > 1000000000) {
int sec = (x->tv_nsec - y->tv_nsec) / 1000000000;
yy.tv_nsec += 1000000000 * sec;
yy.tv_sec -= sec;
}
result->tv_sec = x->tv_sec - yy.tv_sec;
result->tv_nsec = x->tv_nsec - yy.tv_nsec;
}
int int
main(int argc, char *argv[]) main(int argc, char *argv[])
{ {
@ -96,14 +66,10 @@ main(int argc, char *argv[])
char buf[80]; char buf[80];
struct sockaddr_storage client; struct sockaddr_storage client;
struct addrinfo hints, *res, *res0; struct addrinfo hints, *res, *res0;
struct timeval tv; struct itimerval itv;
struct itimerspec ts;
struct sigevent se;
struct sigaction sa;
struct tm *tm; struct tm *tm;
struct pollfd pfd[1]; struct pollfd pfd[1];
socklen_t addrlen; socklen_t addrlen;
timer_t timer;
int ch; int ch;
int nfds, received = 0; int nfds, received = 0;
int error, buffer, last; int error, buffer, last;
@ -145,40 +111,30 @@ main(int argc, char *argv[])
disconnected = 1; disconnected = 1;
memset(&client, 0, sizeof(client)); memset(&client, 0, sizeof(client));
gettimeofday(&tv, NULL);
/* create a timer generating SIGALRM */
memset(&se, 0, sizeof(struct sigevent));
se.sigev_signo = SIGALRM;
se.sigev_notify = SIGEV_SIGNAL;
timer_create(CLOCK_REALTIME, &se, &timer);
/* timer values */ /* timer values */
ts.it_interval.tv_nsec = 100000000; /* 100ms */ itv.it_interval.tv_usec = 100000; /* 100ms */
ts.it_interval.tv_sec = 0; itv.it_interval.tv_sec = 0;
ts.it_value.tv_nsec = 100000000; itv.it_value.tv_usec = 100000;
ts.it_value.tv_sec = 0; itv.it_value.tv_sec = 0;
timer_settime(timer, 0, &ts, NULL); if (setitimer(ITIMER_REAL, &itv, NULL) == -1)
err(2, "setitimer");
/* set SIGALRM handler */ signal(SIGALRM, send_packet);
sa.sa_handler = timer_handler;
sigemptyset(&sa.sa_mask);
sigaddset(&sa.sa_mask, SIGALRM); /* block SIGALRM during handler */
sigaction(SIGALRM, &sa, NULL);
/* send initial packet */ /* send initial packet */
gettimeofday(&sent, NULL); gettimeofday(&sent, NULL);
send_packet(0); send_packet(0);
while (1) { while (1) {
struct timespec now, diff; struct timeval now, diff;
while (1) { while (1) {
pfd[0].fd = sock; pfd[0].fd = sock;
pfd[0].events = POLLIN; pfd[0].events = POLLIN;
nfds = poll(pfd, 1, 200); nfds = poll(pfd, 1, 200);
clock_gettime(CLOCK_REALTIME, &now); gettimeofday(&now, NULL);
timespec_substract(&diff, &now, &sent); timersub(&now, &sent, &diff);
if (nfds > 0) if (nfds > 0)
break; break;
if (nfds == -1 && errno != EINTR) if (nfds == -1 && errno != EINTR)
@ -187,11 +143,11 @@ main(int argc, char *argv[])
printf("%d %s\n", nfds, strerror(errno)); printf("%d %s\n", nfds, strerror(errno));
if (verbose > 1) if (verbose > 1)
printf("wait %ld.%06ld\n", printf("wait %ld.%06ld\n",
(long)diff.tv_sec, diff.tv_nsec/1000); (long)diff.tv_sec, diff.tv_usec);
if (diff.tv_sec > 0 || diff.tv_nsec > 200000000) { if (diff.tv_sec > 0 || diff.tv_usec > 500000) {
if (verbose) if (verbose)
printf("timeout %ld.%06ld\n", printf("timeout %ld.%06ld\n",
(long)diff.tv_sec, diff.tv_nsec/1000); (long)diff.tv_sec, diff.tv_usec);
disconnected++; disconnected++;
nfds = 0; nfds = 0;
break; break;
@ -204,7 +160,7 @@ main(int argc, char *argv[])
tm = localtime((time_t *)&now.tv_sec); tm = localtime((time_t *)&now.tv_sec);
strftime(buf, sizeof(buf), "%F %T", tm); strftime(buf, sizeof(buf), "%F %T", tm);
printf("%s.%06ld: lost connection\n", printf("%s.%06ld: lost connection\n",
buf, now.tv_nsec * 1000); buf, now.tv_usec);
} }
continue; continue;
} }
@ -235,7 +191,7 @@ main(int argc, char *argv[])
tm = localtime((time_t *)&now.tv_sec); tm = localtime((time_t *)&now.tv_sec);
strftime(buf, sizeof(buf), "%F %T", tm); strftime(buf, sizeof(buf), "%F %T", tm);
printf("%s.%06ld: connection is back\n", printf("%s.%06ld: connection is back\n",
buf, now.tv_nsec/1000); buf, now.tv_usec);
if (verbose) if (verbose)
printf("dropped %d paquets\n", seq - last); printf("dropped %d paquets\n", seq - last);
exit(3); exit(3);
@ -245,7 +201,7 @@ main(int argc, char *argv[])
gettimeofday(&sent, NULL); gettimeofday(&sent, NULL);
if (verbose > 1) if (verbose > 1)
printf("%d %ld.%06ld\n", buffer, (long)diff.tv_sec, printf("%d %ld.%06ld\n", buffer, (long)diff.tv_sec,
diff.tv_nsec/1000); diff.tv_usec);
} }
close(sock); close(sock);
exit(0); exit(0);